Peripheral and central venous catheters are increasingly used in clinical practice. However, complications such as local or systemic infections are frequent for both temporary and indwelling vascular catheters. Annually, in the United States of America there are more than 200,000 cases of nosocomial bloodstream infections, of which 90% are related to the use of an intravascular device. These infections are associated with increased morbidity and mortality, prolonged hospitalization and increasing medical costs.
The method of choice when applying an intravascular catheter is first to insert the catheter, and secondly to fix it to the skin by a surgical plaster, possibly followed by draping the insertion site with a transparent adhesive-covered sheet. The most common underlying pathophysiology for the development of infection is the motion of the catheter at the skin insertion site and external contamination of the insertion site due to lack of protection and sterility around the insertion site.
Several devices and methods have been suggested to overcome one or more of these problems, such as those disclosed in GB 1,465,682, WO 80/01458, U.S. Pat. No. 4,698,057 and EP 0 396 497.
GB 1,465,682 describes a cannula fitted close to its rear, or, proximal end with laterally extending wings that are foldable together to form a handle used when inserting the cannula in a patient. Fixed to the wings is one edge of a flexible sheet carrying a layer of pressure-sensitive adhesive covered by a removable barrier sheet. The flexible sheet extends in a direction away from the direction of insertion of the cannula. The adhesive and its barrier sheet are initially facing upwards. Upon insertion of the cannula, the barrier sheet is removed, and the flexible sheet is folded forwardly over on itself to adhere to the wings and to the skin of the patient not only to the rear and to the sides of the wings as well as to exposed portions of the cannula to keep the latter stabilized, but also beyond the wings to cover the point of insertion of the cannula into the skin of the patient. Thus, the device as a whole is attached to the patient, and the wound is covered which is said to protect it from risk of contact or infection. However, since the flexible sheet is connected to the wings by means of two tongues extending from the flexible sheet and serving as hinges during the folding, the areas underneath each such tongue will not adhere to the skin, thus leaving open entries to the insertion site. Furthermore, the flexible tubing leading to the cannula enters the sealed area underneath the flexible sheet adhering to the skin, and this involves a further risk that bacteria may spread along the tubing along its contact with the skin.
WO 80/01458 discloses a stabilizing fitting for an intravenous catheter comprising a flexible base member having on an upper side a cradle adapted to retain a catheter hub, and on a lower surface a pressure-sensitive adhesive covered by a strippable cover sheet. After the catheter has been inserted and brought into a proper position, its hub is press-fitted into the cradle. Then the cover sheet is stripped from the underside of the fitting and the fitting is dabbed onto the patient's skin to stabilize the catheter. This, however, is only a temporary stabilizing, and the fitting is further stabilized by adhesive tapes passing over wings of the fitting. Apart from this evident drawback, there is no teaching as how to possibly avoid contamination of the insertion site. On the contrary, a conventional plaster is shown to cover the insertion site and the forward, or, distal end of the catheter.
U.S. Pat. No. 4,698,057 discloses an assembly for stabilizing and securing an intravascular needle or catheter like device having wings on each side thereof. Each wing has an adhesive tape roll fixed to it. The wings have suction cups on their undersurfaces that cling to the skin of a patient to stabilize the wings and the catheter while adhesive tape is uncoiled from the tape rolls to permanently secure the assembly to the patient. Even if this complicated device may hold the needle satisfactory relative to the skin of a patient, there is no teaching how to prevent contamination of the insertion site.
EP 0 396 497 discloses a hollow cup-shaped cover for protecting an infusion needle disposed through a body portion and into a vein of a patient. The cover has a planar bottom flange that is to be tightly mounted against the skin of a patient, e.g. by means of an adhesive so as to prevent water and other contaminating and infecting matter from contacting the zone of a body portion where a catheter or the like enters the body portion. The wall of the cover is transparent for visual inspection therethrough. In one embodiment, a tube connected to the proximal end of the catheter extends through an aperture in a wall of the cover, and, in another embodiment, a similar tube extends through an arcuate elevated portion of the bottom flange. This device is a complementary device to an intravascular catheter, i.e., it is not integrated with the catheter itself, it is complicated to apply and, thus, does not lend itself to everyday, routine use.
Non of these prior art devices complies with the need to primarily provide a reliable seal all around an insertion site of a catheter, and secondly to provide stabilization of a catheter or a similar tubular means introduced into the body of a patient.
It is a primary object of the present invention, thus, to provide a device which is simple to apply with a secure fixation and with a complete integration of the skin and the catheter at the insertion site, thereby minimizing the risk of nosocomial infections. A secondary object of the present invention is to integrate, in the device, a stabilizing means providing a secure and reliable holding of the catheter in relation to a patient's skin.